{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,6]],"date-time":"2026-10-06T07:40:43Z","timestamp":1791272443749,"version":"4.1.0"},"reference-count":22,"publisher":"American Society for Microbiology","issue":"4","license":[{"start":{"date-parts":[[2007,4,1]],"date-time":"2007-04-01T00:00:00Z","timestamp":1175385600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.asm.org\/non-commercial-tdm-license"}],"content-domain":{"domain":["journals.asm.org"],"crossmark-restriction":true},"short-container-title":["Infect Immun"],"published-print":{"date-parts":[[2007,4]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n          <jats:p>\n            <jats:italic>Toxoplasma gondii<\/jats:italic>\n            is a ubiquitous parasite that persists for the life of a healthy mammalian host. A latent, chronic infection can reactivate upon immunosuppression and cause life-threatening diseases, such as encephalitis. A key to the pathogenesis is the parasite's interconversion between the tachyzoite (in acute infection) and bradyzoite (in chronic infection) stages. This developmental switch is marked by differential expression of numerous, closely related surface proteins belonging to the SRS (\n            <jats:italic>S<\/jats:italic>\n            AG1-\n            <jats:italic>r<\/jats:italic>\n            elated\n            <jats:italic>s<\/jats:italic>\n            equence) superfamily. To probe the functions of bradyzoite-specific SRSs, we created a bioluminescent strain lacking the expression of SRS9, one of the most abundant SRSs of the bradyzoite stage. Imaging of mice intraperitoneally infected with tachyzoites revealed that during an acute infection, wild-type and \u0394\n            <jats:italic>srs9<\/jats:italic>\n            strains replicated at similar rates, disseminated systemically following similar kinetics, and initially yielded similar brain cyst numbers. However, during a chronic infection, \u0394\n            <jats:italic>srs9<\/jats:italic>\n            cyst loads substantially decreased compared to those of the wild type, suggesting that SRS9 plays a role in maintaining parasite persistence in the brain. In oral infection with bradyzoite cysts, the \u0394\n            <jats:italic>srs9<\/jats:italic>\n            strain showed oral infectivity and dissemination patterns indistinguishable from those of the wild type. When chronically infected mice were treated with the immunosuppressant dexamethasone, however, the \u0394\n            <jats:italic>srs9<\/jats:italic>\n            strain reactivated in the intestinal tissue after only 8 to 9 days, versus 2 weeks for the wild-type strain. Thus, SRS9 appears to play an important role in both persistence in the brain and reactivation in the intestine. Possible mechanisms for this are discussed.\n          <\/jats:p>","DOI":"10.1128\/iai.01862-06","type":"journal-article","created":{"date-parts":[[2007,2,2]],"date-time":"2007-02-02T17:24:59Z","timestamp":1170437099000},"page":"1626-1634","update-policy":"https:\/\/doi.org\/10.1128\/asmj-crossmark-policy-page","source":"Crossref","is-referenced-by-count":125,"title":["Bradyzoite-Specific Surface Antigen SRS9 Plays a Role in Maintaining\n            <i>Toxoplasma gondii<\/i>\n            Persistence in the Brain and in Host Control of Parasite Replication in the Intestine"],"prefix":"10.1128","volume":"75","author":[{"given":"Seon-Kyeong","family":"Kim","sequence":"first","affiliation":[{"name":"Department of Microbiology and Immunology, Stanford University School of Medicine, 299 Campus Dr., Stanford, California 94305"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ariela","family":"Karasov","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Immunology, Stanford University School of Medicine, 299 Campus Dr., Stanford, California 94305"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"John C.","family":"Boothroyd","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Immunology, Stanford University School of Medicine, 299 Campus Dr., Stanford, California 94305"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"235","reference":[{"key":"e_1_3_2_2_2","first-page":"1113","volume":"106","year":"2005","unstructured":"Beilhack, A., S. Schulz, J. Baker, G. F. Beilhack, C. B. Wieland, E. I. Herman, E. M. Baker, Y. A. Cao, C. H. Contag, and R. S. Negrin. 2005. In vivo analyses of early events in acute graft-versus-host disease reveal sequential infiltration of T-cell subsets. Blood106:1113-1122.","journal-title":"Blood"},{"key":"e_1_3_2_3_2","doi-asserted-by":"publisher","DOI":"10.1007\/BF00931730"},{"key":"e_1_3_2_4_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.micinf.2005.06.023"},{"key":"e_1_3_2_5_2","first-page":"99","volume":"40","year":"2001","unstructured":"Djurkovic-Djakovic, O., and V. Milenkovic. 2001. Murine model of drug-induced reactivation of Toxoplasma gondii. Acta Protozool.40:99-106.","journal-title":"Acta Protozool."},{"key":"e_1_3_2_6_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0166-6851(97)00210-7"},{"key":"e_1_3_2_7_2","doi-asserted-by":"publisher","DOI":"10.1046\/j.1365-2958.2000.02014.x"},{"key":"e_1_3_2_8_2","first-page":"606","volume":"9","year":"2002","unstructured":"He, X.-L., M. E. Grigg, J. C. Boothroyd, and K. C. Garcia. 2002. Structure of the immunodominant surface antigen from the Toxoplasma gondii SRS superfamily. Nat. Struct. Biol.9:606-611.","journal-title":"Nat. Struct. Biol."},{"key":"e_1_3_2_9_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1462-5822.2005.00517.x"},{"key":"e_1_3_2_10_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0166-6851(01)00297-3"},{"key":"e_1_3_2_11_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijpara.2003.12.004"},{"key":"e_1_3_2_12_2","doi-asserted-by":"publisher","DOI":"10.4049\/jimmunol.174.12.8038"},{"key":"e_1_3_2_13_2","doi-asserted-by":"publisher","DOI":"10.1046\/j.1365-2958.1996.6501361.x"},{"key":"e_1_3_2_14_2","doi-asserted-by":"publisher","DOI":"10.1006\/expr.1994.1054"},{"key":"e_1_3_2_15_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.1102901"},{"key":"e_1_3_2_16_2","doi-asserted-by":"publisher","DOI":"10.1128\/jcm.20.1.133-135.1984"},{"key":"e_1_3_2_17_2","doi-asserted-by":"publisher","DOI":"10.4049\/jimmunol.173.4.2725"},{"key":"e_1_3_2_18_2","doi-asserted-by":"publisher","DOI":"10.1038\/86373"},{"key":"e_1_3_2_19_2","doi-asserted-by":"publisher","DOI":"10.1017\/S0031182003004736"},{"key":"e_1_3_2_20_2","doi-asserted-by":"publisher","DOI":"10.1128\/IAI.73.2.695-702.2005"},{"key":"e_1_3_2_21_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.8469986"},{"key":"e_1_3_2_22_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0020-7519(00)00124-7"},{"key":"e_1_3_2_23_2","first-page":"45","volume":"219","year":"1996","unstructured":"Tomavo, S. 1996. The major surface proteins of Toxoplasma gondii: structures and functions. Curr. Top. Microbiol. Immunol.219:45-54.","journal-title":"Curr. Top. Microbiol. Immunol."}],"container-title":["Infection and Immunity"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/IAI.01862-06","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/IAI.01862-06","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,3,5]],"date-time":"2022-03-05T07:05:37Z","timestamp":1646463937000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.asm.org\/doi\/10.1128\/IAI.01862-06"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2007,4]]},"references-count":22,"journal-issue":{"issue":"4","published-print":{"date-parts":[[2007,4]]}},"alternative-id":["10.1128\/IAI.01862-06"],"URL":"https:\/\/doi.org\/10.1128\/iai.01862-06","relation":{},"ISSN":["0019-9567","1098-5522"],"issn-type":[{"value":"0019-9567","type":"print"},{"value":"1098-5522","type":"electronic"}],"subject":[],"published":{"date-parts":[[2007,4]]},"assertion":[{"value":"2006-11-26","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2007-01-21","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2007-04-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}